Different Types of Telescopes

Our human eye could not read the writing on a nickel 200 feet away. We would need aperture and magnification for this. We would need a telescope. It could be a simple, hand held refractor telescope, with an objective lens for aperture and an eyepiece lens for magnification; these two items incorporated in a cardboard tube would make a telescope, and allow us to read the writing on the nickel.

There are three types of telescopes:

1. The refractor telescope, mentioned above, incorporates lenses to magnify objects. We; however, in the case of any telescope, are concerned more with aperture. The larger the objective lens on the front end of the refractor telescope, the more brightness, or light will be acquired. We can use any combination or type of eyepiece for magnification.

2. The reflector telescope. This type uses mirrors for aperture, or collection of light. The larger the mirror, the more resolute the image. For example, an eight inch mirror would give the viewer a much clearer picture of Saturn's rings than a four inch mirror. Magnification, again occurs with the eyepiece lens, which can be changed for magnification purposes.

3. The Cacladioptric telescope. This type telescope uses mirrors and lenses. This results in a shorter, more mobile tube.

Your telescope can be hand held for views of items on earth. In fact, it would serve similarly as would binoculars. However; for viewing of the heavens, you would want to stabilize your telescope on a tripod. This can vary from a rudimentary three legged device, to a motorized equatorial mount that would track what you are viewing with the rotation of the Earth.

The most important thing to remember, in summary is that aperture, or the larger the lens, or mirror, the more brightness is taken in and the clearer the image. Magnification results from the eyepiece lens, and can be changed by the observer.

In the future, the large Hubble space telescope will be replaced with even larger aperture telescopes. Telescopes launched into space have an advantage over earth mounted telescopes, in that they are clear of any interference of our atmosphere. This makes a profound difference. The views of other galaxies, nebulae, other planets and many more heavenly bodies are crystal clear. This was not always the case for the Hubble space telescope. When first launched, scientists were terribly disappointed to find that the mirror in the telescope had not been ground correctly, resulting in a distorted and unclear image. Billions of dollars had been spent on building and launching the telescope; and now, it did not work. However; scientists developed a "fix" for the flaw and on a future space shuttle mission astronauts performed a space walk and installed the correction. The pictures were then breathtaking.

We do not know what future telescopes in space will reveil to us, but rest assured, the heavenly bodies will be spectuacular.